1. Field of the Invention
The present invention relates to a method of supporting a printed circuit board, a method of mounting electric components, and others, and in particular to the art of supporting a printed circuit board on the side of one surface thereof.
2. Related Art Statement
A printed circuit board (xe2x80x9cPCBxe2x80x9d) is subjected to various operations, such as mounting thereon of electric components (xe2x80x9cECsxe2x80x9d) to produce an electric circuit (e.g., an electronic circuit); screen-printing thereon of a creamed solder; and application thereto of an adhesive by a dispenser. During the operation or each of the operations, the PCB may be supported on the side of one surface thereof opposite to the other surface thereof on which the operation or each operation is carried out. For example, in the case where the PCB has a large size and/or a low rigidity, a central portion of the PCB may sag down so that one or more ECs may not be accurately mounted thereon or the creamed solder may not be uniformly printed thereon. To avoid this, the above-indicated one surface (hereinafter, referred to as the xe2x80x9coperationxe2x80x9d surface) of the PCB is supported so that the opposite surface (hereinafter, referred to as the xe2x80x9csupportedxe2x80x9d surface) thereof may be kept flat.
To this end, it has conventionally been practiced that the entire supported surface of the PCB is supported on a PCB support table by being sucked thereagainst, or that the PCB is supported on a plurality of iron pins. However, the former manner cannot be employed, for example, in a particular case where ones or more ECs have already been mounted on the supported surface of the PCB. On the other hand, the latter manner can be employed in the particular case, because the iron pins can be positioned to support respective small portions of the supported surface of the PCB while avoiding the EC or ECs mounted thereon. However, neither of the two manners can prevent the PCB from being vibrated.
The PCB may be vibrated because of, e.g., an impact produced when an EC is contacted with, and mounted on, the PCB, or an impact produced when the movement of the PCB in a direction parallel to the plane thereof is started or stopped. There arises no problem if the vibration disappears before the EC is actually mounted on the PCB. If not, the EC may be mounted at an inaccurate position on the PCB. That is, the accuracy of mounting of ECs is lowered.
Meanwhile, there is known an EC mounting system including a plurality of EC mounting heads which hold respective ECs; a first moving device which sequentially moves the EC mounting heads to a predetermined EC-mount position; a movable table which supports a PCB; and a second moving device which moves the movable table so that a plurality of predetermined EC-mount places on the PCB are sequentially positioned at a position, corresponding to the EC-mount position, where the EC mounting heads mount the respective ECs on the PCB. In this system, the starting and stopping of movement of the EC mounting heads or the PCB are repeated at a short cycle time and, before the vibration of the PCB due to one starting or stopping disappears, the next starting or stopping occurs. Thus, the vibration of the PCB is amplified, and the degree of inaccuracy of EC mounting is increased. This sort of EC mounting system is required to shorten its cycle time for the purpose of improving its EC-mounting efficiency. If the acceleration or deceleration of movement of the EC mounting heads or the PCB is increased to achieve this purpose, the vibration of the PCB will be further amplified.
In the case where no ECs are mounted on the supported surface of the PCB, the vibration of the PCB can be prevented by supporting the entire supported surface of the PCB with a member (e.g., sponge rubber) having a vibration damping ability. However, in the case where one or more ECs are mounted on the supported surface of the PCB, it is impossible to support the entire supported surface of the PCB. Accordingly, it cannot help using a plurality of iron pins for supporting respective small portions of the supported surface of the PCB while avoiding the EC or ECs mounted thereon. In this case, however, the vibration of the PCB cannot be effectively prevented. Moreover, since the EC or ECs mounted on the PCB behave as some mass, the vibration of the PCB is amplified to some degree, which leads to complicating the problem.
It is therefore an object of the present invention to provide a method of supporting a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a device for supporting a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a method of mounting electric components on a printed circuit board, with reduced vibration of the board.
It is another object of the present invention to provide a member for supporting a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a kit for providing a plurality of members each of which supports a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a material for providing a plurality of members each of which supports a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a method of producing a device for supporting a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
It is another object of the present invention to provide a jig for producing a device for supporting a printed circuit board on the side of one surface thereof, with reduced vibration of the board.
The present invention provides a printed-circuit-board (xe2x80x9cPCBxe2x80x9d) supporting method, a PCB supporting device, an electric-component mounting method, a PCB supporting member, a PCB-supporting-member providing kit, a PCB-supporting-member providing material, a PCB-supporting-device producing method, and a PCB-supporting-device producing jig which have one or more of the technical features that are described below in respective paragraphs given parenthesized sequential numbers (1) to (30). Any technical feature which includes another technical feature shall do so by referring, at the beginning, to the parenthesized sequential number given that technical feature. Thus, two or more of the following features may be combined, if appropriate. Each feature may be accompanied by a supplemental explanation, as needed. However, the following features and the possible combinations thereof are just examples to which the present invention is by no means limited.
(1) According to a first feature of the present invention, there is provided a method of supporting a printed circuit board, comprising the step of causing a contact portion of at least one board supporting member including a vibration damping portion formed of a vibration damping rubber, to contact at least one portion of a lower surface of the printed circuit board and thereby support the printed circuit board on a side of the lower surface thereof. The printed circuit board (xe2x80x9cPCBxe2x80x9d) is supported by the board supporting member including the vibration damping. portion. Therefore, even if the PCB may be vibrated when an electric component (xe2x80x9cECxe2x80x9d) is mounted on the PCB or when the movement of the PCB in a direction parallel to the plane of the PCB is started or stopped, the energy of the vibration is absorbed by the vibration damping portion or rubber and accordingly the vibration of the PCB is prevented. For example, even if a number of ECs are sequentially contacted with the PCB while the starting and stopping of movement of the PCB are repeated, the vibration of the PCB is effectively prevented and the ECs are accurately mounted on the PCB. In the case where ECs are temporarily fixed to the PCB with a creamed solder or an adhesive, the ECs are effectively prevented from being dislocated on the PCB. In the case where a dispenser applies an adhesive to the PCB, the vibration of the PCB is prevented and the adhesive can be applied in appropriate amount and shape to the PCB. In a particular case where the dispenser is provided with a stopper which contacts the PCB and thereby keeps a predetermined distance between the dispenser and the PCB, the stopper could not stably contact the PCB if the PCB would be vibrated. However, according to the present method, the vibration of the PCB is prevented, so that the stopper can stably contact the PCB. Since the predetermined distance is kept between the dispenser and the PCB, the adhesive can be applied in appropriate amount and shape to the PCB. Also in the case where the dispenser is provided with no stopper, the vibration of the PCB is prevented and accordingly a predetermined distance is kept between the dispenser and the PCB, so that the adhesive can be applied in appropriate amount and shape to the PCB. Meanwhile, the PCB supporting member contacts only a portion of the lower surface of the PCB. This portion can be selected such that the selected portion is free from the EC or ECs mounted on the lower surface or the creamed solder applied on the same. Thus, the PCB supporting member is prevented from interfering with the EC or ECs and/or the creamed solder on the lower surface of the PCB. The present method may employ either a single PCB supporting member, or a plurality of PCB supporting members. In the latter case, it is preferred that the plurality of PCB supporting members support a plurality of uniformly distributed portions of the lower surface of the PCB, respectively, and that the distance between each pair of adjacent portions of the PCB supported by a corresponding pair of PCB supporting members be as short as possible. That is, it is preferred that the lower surface of the PCB do not have any broad portions each of which is not supported by any PCB supporting members.
(2) According to a second feature of the present invention that includes the first feature (1), the vibration damping portion comprises the contact portion. The PCB supporting member may be entirely formed of the vibration damping rubber. However, this is not essentially required. In fact, the PCB supporting member which includes the vibration damping rubber as only a portion thereof can prevent the vibration of the PCB, and can be produced at low cost. The vibration damping portion comprising the contact portion can effectively prevent the vibration of the PCB, because the vibration damping portion directly contacts the PCB and directly absorbs the energy of the vibration.
(3) According to a third feature of the present invention that includes the first or second feature (1) or (2), the step of causing the contact portion of the at least one board supporting member comprises causing respective contact portions of a plurality of board supporting members each of which includes a vibration damping portion formed of a vibration damping rubber, to contact respective portions of the lower surface of the printed circuit board. The more the portions of the PCB that are supported by the PCB supporting members are, the more vibration of the PCB is prevented.
(4) According to a fourth feature of the present invention that includes the third feature (3), the step of causing the respective contact portions of the board supporting members comprises turning one of a plurality of printed circuit boards, upside down, such that a first surface thereof as a lower surface thereof to be contacted by the contact portions of the board supporting members faces upward, placing the board supporting members on the first surface of the one printed circuit board, such that the contact portions of the board supporting members are contacted with the portions of the first surface, respectively, placing at least one support plate on respective end surfaces of the board supporting members which surfaces are opposite to the respective contact portions thereof, in a state in which the support plate is positioned relative to the one printed circuit board, fixing the support plate and the end surfaces of the board supporting members to each other, thereby producing a printed-circuit-board supporting device, turning the printed-circuit-board supporting device upside down, and causing the board supporting members of the printed-circuit-board supporting device to sequentially support each of the printed circuit boards. The present method may be carried out in various cases, e.g., in the case where ECs are mounted on each of the PCBs, or in the case where a dispenser applies an adhesive to each of the PCBs. In these specific two cases, it is preferred to support each PCB while preventing the vibration thereof. The vibration of each PCB is prevented by the PCB supporting members each of which includes the vibration damping portion formed of the vibration damping rubber. The PCB supporting members are placed on respective supportable portions of the first surface of each PCB that can be supported by the supporting members, that is, are free from, e.g., the ECs mounted on the first surface or the adhesive applied to the same. The support plate is placed on, and fixed to, the PCB supporting members. Thus, the PCB supporting device for supporting the supportable portions of the first surface of each PCB is easily produced. After the PCB supporting device is produced, the device is turned upside down so that the PCB supporting members of the device support each of the PCBs. To this end, the PCB supporting device is positioned relative to each PCB in the same relationship as that in which the support plate is positioned relative to the placed PCB for producing the supporting device. Thus, the PCB supporting members of the supporting device are reliably contacted with the supportable portions of the first surface of each PCB that are free from, e.g., the ECs mounted on the first surface. That is, the PCB supporting members support each PCB without interfering the ECs mounted thereon. The dimension of each of the PCB supporting members as measured in a PCB-support direction perpendicular to the first surface of each PCB, can be selected such that a large space is defined between the respective end surfaces of the contact portions of the PCB supporting members that are contacted with the each PCB and a support surface of the support plate to which the supporting members are fixed, the large surface having a dimension greater than, e.g., the height of the tallest one of all the ECs mounted on the first surface of the each PCB. Thus, the PCB supporting device can support the each PCB, while preventing the support plate thereof from interfering with the ECs mounted on the PCB. In the case where a height-adjust plate is used as fixed to the support plate, different sorts of PCB supporting members having different lengths corresponding to different sorts of ECs having different heights, respectively, may be used in mixture for producing a PCB supporting device. In this case, the PCB supporting device defines a stepped space which allows the different sorts of supporting members to support each PCB, while preventing the support plate thereof from interfering with the different sorts of ECs mounted on the PCB. When the support plate is set and positioned relative to the PCB, the plurality of PCB supporting members are set and positioned relative to the PCB, all at once; and when the support plate is removed, all the PCB supporting members are removed at once. The present method may be carried out in the case where a creamed solder is screen-printed on each of the PCBs. In this case, only a member for screen-printing the creamed solder is moved relative to each PCB and a screen and accordingly the vibration of the each PCB is not serious. Accordingly, it is required that the PCB be supported with a high degree of flatness rather than with reduced vibration. Thus, it is preferred that at least one of the PCB supporting members include a rigid portion formed of a rigid material such as aluminum.
(5) According to a fifth feature of the present invention that includes the fourth feature (4), the step of fixing the support plate and the end surfaces of the board supporting members comprises fixing the support plate and the end surfaces of the board supporting members via respective tacky layers formed on the end surfaces. Each of the tacky layers includes a tacky material that is not hardened even if it is left exposed to the ambient air at room temperatures. Therefore, each tacky layer can be used repeatedly. Depending upon the material of the support plate, the PCB supporting members which have been once used with the support plate may be removed from the support plate and used again for producing another PCB supporting device.
(6) According to a sixth feature of the present invention that includes the fourth or fifth feature (4) or (5), the step of placing the board supporting members on the first surface of the placed printed circuit board comprises fitting a spacer member on an outer surface of the contact portion of at least one of the board supporting members, thereby preventing the contact portion of the one board supporting member from contacting an electric component mounted on the first surface. In view of the accuracy of positioning of each PCB and each of the PCB supporting members and the accuracy of mounting of each of the ECs, it is preferred that a space greater than a predetermined value (e.g., 1 mm) be provided between one or more ECs mounted on the first surface of each PCB and the contact portion of each PCB supporting member, so that the contact portion is prevented from contacting the ECs. The spacer member whose thickness is not smaller than the predetermined value may first be placed on a supportable portion of the first surface that is free from the ECs and then the contact portion of one PCB supporting member may be fitted in an inner space of the spacer member. Alternatively, the spacer member which is fitted in advance on the contact portion of one PCB supporting member may be placed with the contact portion on a supportable portion of the first surface that is free from the ECs. In either manner, subsequently, the one PCB supporting member is fixed to the support plate. Then, the spacer member is removed from the contact portion of the one supporting member. In the present method, the PCB supporting members can support each PCB without interfering with the ECs mounted on the PCB, even if the ECs have been mounted on the PCB with some positional errors. The spacer member has a shape corresponding to the profile of a transverse cross section of the contact portion of one PCB supporting member, taken along a plane perpendicular to the PCB-support direction of the supporting member. However, it is not essentially required that the spacer member be provided by an annular member. The spacer member may be provided by a member which is not continuous in a portion thereof. The spacer member is only required to have a shape which allows the spacer member to be fitted on the contact portion of one PCB supporting member.
(7) According to a seventh feature of the present invention, the r e is provided a printed-circuit-board PCB-supporting device for contacting a plurality of portions of a first one of opposite surfaces of a printed circuit board, and thereby supporting the printed circuit board on a side of the first surface, comprising at least one support plate; and a plurality of board supporting members which are fixed t o a plurality of portions of the support plate, respectively, each of the board supporting members including a vibration damping portion formed of a vibration damping rubber. The plurality of PCB supporting members support the plurality of supportable portions of the first surface of the PCB, respectively, while the respective vibration damping portions of the supporting members cooperate with each other to prevent the vibration of the PCB. Since a plurality of PCB supporting members are fixed to a plurality of portions of the support plate, respectively, those PCB supporting members can be set and reset relative to the PCB, all at once. Since the PCB supporting device is provided by the support plate and the plurality of PCB supporting members, the supporting device enjoys a simple construction and a low production cost.
(8) According to an eighth feature of the present invention that includes the seventh feature (7), the vibration damping portion of the each of the board supporting members comprises a contact portion which contacts a corresponding one of the plurality of portions of the first surface of the printed circuit board. Since the vibration contact portion directly contacts the PCB, the each PCB supporting member can effectively prevent the vibration of the PCB.
(9) According to a ninth feature of the present invention that includes the seventh or eighth feature (7) or (8), the support plate comprises at least one reference portion for being positioned relative to the printed circuit board. When the PCB supporting members are attached to the support plate, or when the support plate to which the supporting members have been attached is attached to a PCB positioning and supporting device, the reference portion of the support plate is used as a reference for positioning the support plate relative to the PCB.
(10) According to a tenth feature of the present invention, there is provided a method of mounting a plurality of electric components, comprising the steps of causing a movable table which is movable to an arbitrary position on a substantially horizontal plane, to support a lower surface of a printed circuit board via at least one board supporting member including a vibration damping portion formed of a vibration damping rubber, and causing a plurality of mounting heads to hold the plurality of electric components, respectively, and moving the plurality of mounting heads to sequentially reach a predetermined component-mount position where the plurality of mounting heads sequentially mount the plurality of electric components at a plurality of component-mount places, respectively, on an upper surface of the printed circuit board supported by the movable table via the board supporting member, while the printed circuit board is moved with the movable table. The present EC mounting method may be carried out by an EC mounting apparatus which includes an intermittent-rotation body which is intermittently rotatable about an axis line at an intermittent-rotation angular pitch; a plurality of EC mounting heads which are provided on the intermittent-rotation body such that the EC mounting heads are equiangularly spaced from each other at a spacing angular pitch equal to the intermittent-rotation angular; and an intermittently rotating device which intermittently rotates the intermittent-rotation body about the axis line, so that the EC mounting heads are sequentially moved to each of a plurality of operation positions such as an EC-pick-up position and an EC-mount position. The present method may also be carried out by an apparatus disclosed in Japanese Patent Application laid open for public inspection under Publication No. 9-237997, corresponding to U.S. Pat. application Ser. No. 8-769,700 now U.S. Pat. No. 5,926,950. This apparatus includes a plurality of rotary members which are rotatable about a common axis, independent of each other; a rotary-motion applying device which applies, to each of the rotary members, such a rotary motion that the each rotary member is rotated 360 degrees about the common axis line, during the 360-degree rotation the each rotary member is stopped at least one time, and the each rotary member has a predetermined time difference from each of its preceding and following rotary members; and a plurality of EC mounting heads which are supported by the plurality of rotary members, respectively, and which can hold respective ECs. Moreover, the present method may be carried out by an apparatus which includes a rotatable body which is rotatable about an axis line; a plurality of EC mounting heads which are provided on the rotatable body; and a rotating device which rotates the rotatable body by arbitrary angles, so that the EC mounting heads are sequentially moved to an EC-mount position. In each of the three apparatuses, the plurality of EC mounting heads are moved to the EC-mount position at a short time interval, that is, a short cycle time, so that the EC mounting heads mount respective ECs on a PCB. Furthermore, the present method may be carried out by an apparatus which includes a movable table which supports a PCB and which is movable in one of two directions perpendicular to each other on a plane; a plurality of EC mounting heads which hold respective ECs; and a head moving device which moves the EC holding heads in the other direction. While the EC holding heads are sequentially moved to the EC-mount position, the PCB is moved so that predetermined EC-mount places on the PCB are sequentially moved to a position corresponding to the EC-mount position. Thus, at the EC-mount position, the EC holding heads sequentially mount the respective ECs on the PCB, at a short cycle time. Therefore, if the vibration of the PCB would not be effectively prevented, the mounting of the current EC on the PCB would occur before the vibration of the PCB disappears which is produced when the prior EC is contacted with, and mounted on, the PCB, when the EC holding head releases the prior EC and is moved away from the same, or when the PCB is moved for the current EC to be mounted thereon. This leads to lowering the accuracy of mounting of ECs. This problem will be more serious in the case where the cycle time of EC mounting is shortened to improve the efficiency of EC mounting. In the present method, since the PCB supporting member including the vibration damping portion supports the PCB, the vibration damping portion absorbs the energy of the vibration exerted to the PCB, thereby preventing the vibration of the PCB. Therefore, it is not needed to reduce the acceleration and/or deceleration of movement of the movable portions (the heads, the table, etc.), for the purpose of preventing the vibration of the PCB. This leads to improving the efficiency of EC mounting. In the case where the EC mounting efficiency may not be improved, the accuracy of EC mounting may be improved. The supplying of ECs to the EC mounting heads may be carried out in such a manner that a plurality of EC feeders are provided on a movable table such that respective EC-supply portions thereof are arranged along a single line and, when the movable table is moved, the respective EC-supply portions are sequentially moved to an EC-supply position right below one EC mounting head being positioned at the EC-pick-up position. In this case, a PCB is vibrated when the movement of the movable table is started and stopped. This vibration of the PCB is effectively prevented by the PCB supporting member, so that the ECs are accurately mounted on the PCB.
(11) According to an eleventh feature of the present invention, there is provided a printed-circuit-board supporting member for contacting a portion of a first one of opposite surfaces of a printed circuit board, and thereby supporting the printed circuit board on a side of the first surface, comprising a vibration damping portion formed of a vibration damping rubber; and a fixing device which fixes one end of the printed-circuit-board supporting member to a support plate, the fixing device being provided at the one end of the supporting member, the vibration damping portion providing a complete transverse portion between the one end of the supporting member and a contact end of the supporting member which end contacts the portion of the first surface of the printed circuit board. The complete transverse portion which consists of the vibration damping rubber only completely occupies a portion of the PCB supporting member along a flat or curved surface intersecting the PCB-support direction of the supporting member. Therefore, the vibration transmitted from the PCB to the contact end of the PCB supporting member must pass, at least one time, through the complete transverse portion, before the vibration reaches the fixing device. It can be said that the PCB supporting member can be cut into two separate portions at the above-indicated flat or curved surface, or alternatively it can be said that any vibration-transmission route between the contact end of the PCB supporting member and the fixing device must pass, at least one time, through the vibration damping rubber. In the present PCB supporting member, the vibration damping rubber reliably absorbs the energy of the vibration exerted to the PCB.
(12) According to a twelfth feature of the present invention that includes the eleventh feature (11), the fixing device comprises a tacky layer formed on an end surface of the one end.
(13) According to a thirteenth feature of the present invention that includes the eleventh feature (11), the fixing device comprises a permanent magnet provided at the one end.
(14) According to a fourteenth feature of the present invention that includes any one of the eleventh to thirteenth features (11) to (13), the vibration damping portion has the contact end which contacts the portion of the first surface of the printed circuit board, and wherein the printed-circuit-board supporting member further comprises a secondary portion which supports the vibration damping portion. The vibration damping portion which directly contacts the first surface of the PCB can effectively prevent the vibration of the PCB. The PCB supporting member including the secondary portion can be produced at a lower cost than a PCB supporting member which is entirely formed of the vibration damping rubber. For example, in the case where one or more tall ECs are mounted on the first surface of the PCB, it is needed to use one or more long PCB supporting members. If the long supporting members are ones which are entirely formed of the vibration damping rubber, they cost high. In contrast, the present PCB supporting member includes the secondary portion which may be formed of a material cheaper than the vibration damping rubber. Thus, one or more long PCB supporting members can be produced at low cost. Meanwhile, when a PCB supporting device including at least one support plate and at least one PCB supporting member supports a PCB, the support plate may be positioned, in a PCB-support direction of the device, at a position which is appropriate for one or more long PCB supporting members to support a PCB on which one or more tall ECs are mounted. In this case, if one or more short PCB supporting members are attached to one or more support plates for producing a PCB supporting device, the short PCB supporting members on the support plates being positioned at the above-indicated appropriate position, however, cannot reach the PCB. The secondary portion of the present PCB supporting member may compensate for the shortage of each of the short PCB supporting members. In this case, each of different sorts of PCB supporting devices for supporting different sorts of PCBS, respectively, can be produced by using one or more support plates positioned at the above-indicated appropriate position unchanged.
(15) According to a fifteenth feature of the present invention that includes the fourteenth feature (14), the secondary portion is formed of a foamed material. The foamed material may be a urethane rubber or a sponge rubber. The foamed material is light, cheap, and is not elastically deformed so largely due to a small mass of a PCB and/or a small contact load at which each mounting head holding an EC contacts the PCB to mount the EC thereon.
(16) According to a sixteenth feature of the present invention that includes any one of the eleventh to fifteenth features (11) to (15), the printed-circuit-board supporting member further comprises a support pin which projects from an end surface of the printed-circuit-board supporting member which surface is opposite to the one end, the support pin having the contact end. One or more PCB supporting members each of which includes a support pin can support the first surface of the PCB on which the ECs are mounted at a high density or only small spaces are left among the mounted ECs (or the applied adhesive or the applied creamed solder).
(17) According to a seventeenth feature of the present invention that includes any one of the eleventh to fifteenth features (11) to (15), the printed-circuit-board supporting member further comprises a contact portion which includes the contact end and which is opposite to the one end, the contact portion having at least one recess so that a profile of a transverse cross section of the contact portion includes at least one inwardly deformed portion corresponding to the at least one recess. The shape, dimensions, and/or number of one or more recesses of the PCB supporting member may be predetermined, depending upon the shape, dimensions, and/or number of one or more ECs mounted on the first surface of the PCB, so that the PCB supporting member can support a supportable portion of the first surface of the PCB which portion is free from the ECs. In this case, the PCB supporting member does not interfere with the ECs. In addition, if a number of PCB supporting members are used, the total area of the respective contact portions of the PCB supporting members will be large, which leads to preventing more effectively the vibration of the PCB. The recess or recesses is or are not limited to one or ones which has or have a surface intersecting the PCB-support direction of the PCB supporting member, but may be a groove or grooves which extends or extend through the PCB supporting member in its PCB-support direction. In the case where one or more members other than the EC or ECs, such as the applied adhesive or the applied creamed solder is or are mounted on the first surface of the PCB, the PCB supporting member including one or more recesses may be used to support the PCB without interfering with the member or members.
(18) According to an eighteenth feature of the present invention that includes any one of the eleventh to seventeenth features (11) to (17), the printed-circuit-board supporting member further comprises a head portion having the contact end; a base portion which supports the head portion and includes the fixing device and which is provided separately from the head portion; and a connecting device which connects the head portion and the base portion to each other such that the head portion and the base portion are separable from each other. According to this feature, a plurality of sorts of head portions may be prepared and each of the head portions may be used with the common base portion. When the current sort of PCBs are changed to a different sort of PCBs, the current sort of PCB supporting member or members-may be changed to a different sort of PCB supporting member or members corresponding to the different sort of PCBs. In this case, the head portion or portions of the current PCB supporting member or members is or are removed from the base portion or portions, and replaced with a different sort of head portion or portions corresponding to the different sort of PCB supporting member or members. This manner costs lower than the manner in which the current sort of PCB supporting member or members is or are entirely replaced with the different sort of PCB supporting member or members.
(19) According to a nineteenth feature of the present invention, there is provided a kit comprising a plurality of printed-circuit-board supporting members each according to any one of the eleventh to eighteenth features (11) to (18); and a common base member to which each of the printed-circuit-board supporting members is detachably attached via the fixing device thereof. A material for providing the common base member may be selected depending upon the fixing devices of the PCB supporting members. For example, the common base member is formed of a peelable sheet or a magnet. Since the fixing device with which each PCB supporting member is fixed to the support plate is utilized to attach the each PCB supporting member to the common base member, the kit may be produced, in many cases, at lower cost than a kit wherein an exclusive fixing device is employed to attach each of a plurality of PCB supporting members to a common base sheet.
(20) According to a twentieth feature of the present invention that includes the nineteenth feature (19), the plurality of printed-circuit-board supporting members include respective contact portions which are opposite to the respective one ends thereof, which contact respective portions of the first surface of the printed circuit board, and which have an identical shape and an identical dimension. In the case where a desired PCB supporting device can be produced using only one sort of PCB supporting members whose respective contact portions have an identical shape and an identical dimension, the preparation of only one sort of kit or kits suffices. On the other hand, in the case where a desired PCB supporting device cannot be produced without using different sorts of PCB supporting members which are different from each other with respect to at least one of shape and dimension of the respective contact portions thereof, different sorts of kits are prepared, and the different sorts of PCB supporting members are removed in respective needed numbers from the different sorts of kits, and are used for producing the desired PCB supporting device. The number of each sort of kits to be prepared can be predetermined based on the frequency of use of the corresponding sort of PCB supporting members for producing a needed number of PCB supporting devices. Thus, the number of each sort of PCB supporting members that are left without being used can be minimized, which leads to reducing the production cost of the PCB supporting devices. In the case where the PCB supporting members provided by the kit include respective secondary portions in addition to the respective contact portions, those secondary portions may, or may not, have an identical shape and an identical dimension.
(21) According to a twenty-first feature of the present invention that includes the nineteenth feature (19), the plurality of printed-circuit-board supporting members include respective contact portions which are opposite to the respective one ends thereof and which contact respective portions of the first surface of the printed circuit board, the plurality of printed-circuit-board supporting members comprising a plurality of sorts of printed-circuit-board supporting members including respective contact portions which are different from each other in at least one of shape and dimension. According to this feature, a single kit provides a plurality of sorts of PCB supporting members. This kit is advantageously used for producing a PCB supporting device which needs two or more sorts of PCB supporting member comprising the plurality of sorts of PCB supporting members provided by the single kit.
(22) According to a twenty-second feature of the present invention that includes any one of the nineteenth to twenty-first feature (19) to (21), the fixing device of each of the printed-circuit-board supporting members comprises a tacky layer formed on an end surface of the one end thereof, and the common base member exhibits a lower degree of tackiness to the tacky layer than the end surface. According to this feature, each of the PCB supporting members can be easily removed from the common base member, in the state in which the each PCB supporting member keeping its tacky layer on its one end surface, so that the each PCB supporting can be fixed to the support member owing to its tacky layer.
(23) According to a twenty-third feature of the present invention that includes any one of the nineteenth to twenty-second feature (19) to (22), the kit further comprising a fitable member which is detachably fitable on an outer surface of a contact portion of at least one of the printed-circuit-board supporting members, so as to increase an apparent cross-section area of the contact portion, when the contact portion of the one supporting member is contacted with a portion of the first surface of the printed circuit board so as to produce a printed-circuit-board supporting device. The fitable member may be a spacer member which is used for securing a clearance between the contact portion of the PCB supporting member and one or more ECs mounted on the first surface of the PCB; or a supporter member for supporting the contact portion of the PCB supporting member that has only a small cross-section area, so that the PCB supporting member can stably stand on the first surface of the PCB.
(24) According to a twenty-fourth feature of the present invention, there is provided a material for providing a plurality of printed-circuit-board supporting members which contact respective portions of a first one of opposite surfaces of a printed circuit board and thereby supports the printed circuit board on a side of the first surface, the material having an elongate shape, the material comprising a vibration damping portion which is located in vicinity of one of opposite side surfaces of the material which extend in a longitudinal direction of the material, the vibration damping portion being formed of a vibration damping rubber; a tacky layer which is located adjacent to the other side surface; and a peelable sheet which covers the tacky layer such that the peelable sheet is peelable from the tacky layer, the material being cutable by a cutter along a plane intersecting the longitudinal direction, into a plurality of pieces which provide the plurality of printed-circuit-board supporting members, respectively. A desired length of the elongate material can be cut off based on the shape and area of any supportable portion of the first surface of the PCB which portion is free from the ECs, the adhesive, or the creamed solder. Thus, the present material can provide a PCB supporting member which has a desired contact or support area corresponding to a desired length and which supports the supportable portion of the first surface via the desired support area. However, the elongate material may be used as it is, without being cut, in the case where the material is used for supporting a large supportable portion of the first surface of the PCB which portion has a large area corresponding to the entire support area of the elongate material.
(25) According to a twenty-fifth feature of the present invention that includes the twenty-fourth feature (24), the material further comprises a secondary layer which is located between the vibration damping portion and the tacky layer and which is formed of a material different from the vibration damping rubber.
(26) According to a twenty-sixth feature of the present invention that includes the twenty-fifth feature (25), the secondary layer is formed of a foamed material.
(27) According to a twenty-seventh feature of the present invention that includes the twenty-fourth feature (24), the cutter is manually operated by an operator.
(28) According to a twenty-eighth feature of the present invention, there is provided a method of producing a printed-circuit-board supporting device which contacts at least one portion of a first one of opposite surfaces of a printed circuit board and thereby supports the printed circuit board on a side of the first surface, the method comprising the steps of placing the printed circuit board such that an upper surface of the placed printed circuit board is defined by the first surface thereof, placing at least one board supporting member on the first surface of the printed circuit board, such that a contact portion of the board supporting member is contacted with the portion of the first surface, placing a support plate on an end surface of the board supporting members which surface is opposite to the contact portion thereof, in a state in which the support plate is positioned relative to the printed circuit board, and fixing the support plate and the end surface of the board supporting member to each other, thereby producing the printed-circuit-board supporting device. The PCB supporting member may be provided, depending upon the goal of use thereof, by one which includes a vibration damping portion and which not only supports the PCB but also damps the vibration of the same; or one which includes no vibration damping portion and whose contact portion is formed of a rigid material such as aluminum. According to this feature, one or more PCB supporting members are placed on one or more supportable portions of the first surface of the PCB that are free from the ECs, the adhesive, or the creamed solder, and one or more support plates are placed on, and fixed to, the respective end surfaces of the PCB supporting members. In this way, a PCB supporting device is easily produced which can support the supportable portions of the first surface of the PCB.
(29) According to a twenty-ninth feature of the present invention, there is provided a jig for producing a printed-circuit-board supporting device which contacts a plurality of portions of a first one of opposite surfaces of a printed circuit board and thereby supports the printed circuit board on a side of the first surface, the printed-circuit-board supporting device including a support plate and a plurality of board supporting members fixed to the support plate, the jig comprising a board holding member which contacts a second one of the opposite surfaces of the printed circuit board and thereby holds the printed circuit board; a first positioning device which positions the printed circuit board relative to the board holding member in a direction parallel to a plane of the printed circuit board; and a second positioning device which positions the support plate relative to the board holding member in a direction parallel to a plane of the support plate and which permits the positioned support plate to be moved toward the printed circuit board. The first positioning device positions the PCB relative to the board holding member, and the second positioning device positions the support plate relative to the same, i.e., the board holding member. Thus, the support plate is positioned relative to the PCB in a direction parallel to the respective planes of the support plate and the PCB. In this state, the second positioning device permits the thus positioned support plate to be moved toward the PCB in a direction perpendicular to the plane of the PCB. In short, the support plate is movable toward the PCB, in the state in which the support plate is positioned relative to the PCB. According to this feature, one or more PCB supporting members is or are placed on one or more supportable portions of the first surface of the PCB held by the board holding member, in such a manner that respective one ends of the PCB supporting members are contacted with the supportable portions of the first surface, and, in this state, one or more support plates is or are moved toward the PCB till the support plates contact the respective other ends of the PCB supporting members. Then, the support plates are fixed to the other ends of the PCB supporting members, so as to produce a PCB supporting device wherein the PCB supporting members are fixed to appropriate portions of the support plates. The present jig enjoys a simple construction, because it is provided by the board holding member and the first and second positioning devices. With this jig, a user can easily produce a PCB supporting device wherein one or more PCB supporting members is or are fixed to one or more desired positions on one or more support plates. The user can more easily produce a PCB supporting device, if he or she uses, in combination with the present jig, the kit according to any one of the nineteenth to twenty-third features (19) to (23).
(30) According to a thirtieth feature of the present invention that includes the twenty-ninth feature (29), the jig further comprises an indicating device which indicates, to an operator, an inhibiting area on the printed circuit board held by the board holding member, an operator being inhibited from placing each of the board supporting members in the inhibiting area on the printed circuit board. The first surface of the PCB may include one or more inhibiting portions or areas which must not be supported by any PCB supporting members. For example, the inhibiting portions or areas may be portions with which one or more PCB positioning members are engaged, or portions which are supported by a PCB conveyor device such as one or more conveyor belts or chains. Since the indicating device indicates, to the operator, the inhibiting area or areas on the first surface of the PCB, he or she can recognize one or more supportable portions of the first surface of the PCB which can be supported by one or more PCB supporting members. Therefore, the PCB supporting device produced using the present jig can support the PCB, while the PCB supporting members of the device are reliably prevented from interfering with the PCB positioning members, the conveyor belts or chains, or the like.